As far as authorized GN'R books and Axl biographies, we have this:
Shattered Illusion that was worked on in the 90s and intended to be released in 1995. The conflicts between Axl and Slash, and Axl and Robert John, may have caused this to be cancelled. But at the very least, a manuscript for this book exists.
Then in the 2000s, Sebastian Bach would reveal that Axl was working on a book which Axl later clarified was more of a "legal record" of the breakup of the band. Maybe Shattered Illusion morphed into this new book more focused on the collapse of the UYI lineup? Regardless, in 2016, Axl would talk about it being quite likely he would release a book, which sounds more like a biography again, but it was obviously difficult to write about what had happened without opening old wounds:
So that's what we have on this matter.
last night I had a dream where I could kinda tell I was in a dream but wasn’t 100% sure so I was like “maybe if I go on the internet I’ll see something so ridiculous that it’ll confirm I’m in a dream,” and it worked (I saw a post saying that Izzy was rejoining GnR)